Scale VM with tags in Azure

Run-VMScale.ps1

<#
    .SYNOPSIS
        This Azure Automation runbook use tags to scape up/down a virtual machine

    .DESCRIPTION
        This runbook will resize a virtual machine based on the tags attached to the Virtual Machine object. Both 'ScaleUpSize' and 'ScaleDownSize'-tags must be present for scaling to work.

        The runbook is ment to be run on two different schedules:
        1. Set 'SCALEUP'=$true to resize a VM to the size set in 'ScaleUpSize'
        2. Set 'SCALEUP'=$false to resize a VM to the size set in 'ScaleDownSize'

        The runbook assumes the Automation account is created with a 'Azure Run as Account'

    .PARAMETER RG
        The Resource group where the Virtual Machine is located

    .PARAMETER VM
        The name of the Virtual Machine to be scaled

    .PARAMETER SCALEUP
        The parameter acts as a switch. If set to 'True', the VM will be scaled up. If 'False' the VM is scaled down.
        Default value is 'False'.
#>

param(
    [parameter(Mandatory=$true)]
    [String] $rg,
    [parameter(Mandatory=$true)]
    [String] $vm,
    [parameter(Mandatory=$false)]
    [bool] $scaleUp=$false
)

try
{
    $connection = Get-AutomationConnection -Name 'AzureRunAsConnection'
    Add-AzureRmAccount `
        -ServicePrincipal `
        -TenantId $connection.TenantId `
        -ApplicationId $connection.ApplicationId `
        -CertificateThumbPrint $connection.CertificateThumbprint | Out-Null
}
catch
{
    if (!$connection)
    {
        $errorMessage = "Connection not found"
        throw $errorMessage
    }
    else
    {
        Write-Error -Message $_.Exception
        throw $_.Exception    
    }
}

if($scaleUp) {
    $scaleTagSwitch = 'ScaleUpSize'
}
else
{
    $scaleTagSwitch = 'ScaleDownSize'
}



$vmdetails = Get-AzureRmVM -ResourceGroupName $rg -Name $vm
$scaleSize = $vmdetails.Tags[$scaleTagSwitch]
$vmSize = $vmdetails.HardwareProfile.VmSize
if(($vmSize -ne $scaleSize) -and ($scaleSize))
{
    Write-Output "Resource Group=$rg, Virtual Machine=$vm, Size=$vmSize, ScaleTagSwitch=$scaleSize"

    $vmState = Get-AzureRmVM -ResourceGroupName $rg -Name $vm -Status
    if($vmState.Statuses[1].DisplayStatus -eq "VM running")
    {
        Write-Output "$vm is running. stopping…"
        Stop-AzureRmVM -ResourceGroupName $rg -Name $vm -Force | Out-Null
    }

    $vmdetails.HardwareProfile.VmSize = $scaleSize
    Update-AzureRmVM -ResourceGroupName $rg -VM $vmdetails | Out-Null
    Start-AzureRmVM -ResourceGroupName $rg -Name $vm | Out-Null
    Write-Output "Resized $vm to $scaleSize"
}